That’s right 10 stops of light blocking power. I’ve had this B+W filter in and out of my bag for years now and have never really given it a good go. 10 stops is almost like trying to look through a piece of tin foil… it’s completely black and shows just a hint of light even when looking at the sun. Here I am at Portland Head Light seeing if I would make the ocean turn to glass. I was shocked that my D750 could still take a meter reading (nice!) but forget about locking down any kind of focus. Here’s the result – 30mm, f16, ISO 100 for 35 seconds. Just love that fluffy look to those waves!